Hizzoner paid back his favorite barista Sunday by officiating at the man’s wedding at City Hall.

Edouard Houilliez, a barista at Patisserie Colson on Ninth Street in Park Slope, Brooklyn, routinely serves de Blasio a cup of joe and an oatmeal or chocolate-chip cookie after the mayor’s morning workout at the nearby YMCA.

So after asking girlfriend Emily Shevenock to marry him in January, the 29-year-old French immigrant popped the question to the mayor: Would he officiate their wedding?